The invention relates to a chip card contacting unit in which the contact array of the chip card is electrically and mechanically contacted by the contacts of the printed circuit board of the contacting unit whereby for ensuring the correct contacting position of the chip card relative to the contacts a switch with an axial stop is provided that limits the axial insertion movement of the chip card.
Such chip card contacting units are known from International Patent Application WO 95/33243. Such contacting units are, for example, used in the form of reading devices in banking, for pay TV as well as an access authorization for data networks, personal computers, etc. For mobile chip card readers and also for mobile telephones in connection with SIM cards a very precise switching function is required due to the miniaturized design because the tolerances relative to one another (housing, printed circuit board, and contacts) considerably effect the switching function and switching reliability. For ensuring the correct contacting position and function of chip card and contacting unit relative to one another, a switch is provided which essentially detects the presence of a chip card in the chip card contacting unit whereby the leading transverse edge of the chip card actuates a means for switching the control, such as a switch spring or a switch lever, so that only after this cooperation a signal transfer from the printed circuit board to the chip card and vice versa is possible. The switch thus informs the chip card contacting unit that a chip card has been inserted and the correct contacting position has been reached so that thereafter data transfer is possible.
A disadvantage of such chip card contacting units is that the inserted chip card is not precisely enough guided by the axial stop that limits its insertion and that it is not automatically forced into a correct switching position. There is always the risk that the chip card is outside the switching hysteresis in the inserted position and that a data transfer is not possible. When unfavorable positioning tolerances are present, for example, of the circuit board relative to the housing, insertion of the chip card past the stop can occur so that the contact array of the chip card is lifted off the contact springs provided at the printed circuit board and switching errors can occur. Also, vibrations and impacts may result in an accidental displacement of the chip card from its contacting position.
It is therefore an object of the present invention to improve a chip card reader of the aforementioned kind while avoiding the aforementioned disadvantages with respect to functional reliability and to increase the contacting reliability for positioning of the chip card in the contacting device.